This invention relates to Hall-element sensors for detecting magnetic fields that exceed a predetermined strength and more particularly to such a sensor having a Hall-element, a Hall-voltage threshold detector and a pair of DC supply terminals through which the sensor receives electrical energy from a remote source and through which the output signal is transmitted to a remote receiver.
It is known to combine in a package a Hall-element with a Hall-voltage threshold detector including amplifier stages, the packaged circuits receiving electrical energy from a remote DC source through power and ground terminals and transmitting an output signal at a third terminal with respect to the ground terminal. Such a three terminal circuit may be made in integrated-circuit form as is described in the patent to Genesi, U.S. Pat. No. 3,816,766 issued June 11, 1974 that is assigned to the same assignee as is the present invention. This integrated circuit also includes an on-board voltage regulator to provide a substantially fixed voltage to the Hall-element and threshold detector for a large range of remote DC supply voltages.
It is an object of the present invention to provide a Hall-element sensor package having only two terminals through which DC power is received and through which the output signal is transmitted.